Crashworthiness of sandwich cylinder filled with double-arrowed auxetic structures under axial impact loading

Bioinspired structure/material has attracted attentions in engineering fields. In this article, a novel sandwich cylinder inspired by shore horsetail is proposed by introducing the double-arrowed auxetic filler. The energy absorption characteristics of the sandwich cylinder are analysed comprehensively and compared to the conventional structure to show its superiority. The effects of the geometric parameters on the energy absorption characteristics are also discussed. It is found that the number of layers and cells for auxetic structures, thickness of beams and thin-walled tubes, and the radius of the inner tube have great effects on the crushing force, energy absorption, initial peak force and specific energy absorption. The sandwich cylinder will be a great energy absorber after designing.